نتایج جستجو برای: scattering

تعداد نتایج: 114757  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید بهشتی - دانشکده علوم 1386

چکیده ندارد.

A simple algorithm is presented for evaluating scattering parameters of a two-port network. This technique uses the indefinite admittance matrix to calculate scattering or any other desired set of two-port parameters.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده علوم پایه 1390

در این پایان نامه در ابتدا با استفاده از روش سل – ژل که روشی کم هزینه است نانو ذرات ktp و zno را تولید می کنیم ، سپس مشخصه یابی ساختاری ، اپتیکی و ریخت شناسی مورد بحث قرار گرفته است. به منظور شناخت فازهای موجود، ساختار و ریخت شناسی نانو ذرات از روش پراش اشعه ایکس (xrd) ، طیف سنجی پس پراکندگی میکرو رامان (raman scattering) و میکروسکپ الکترونی روبشی (sem) استفاده گردیده است به کمک طیف سنجی های پ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان - دانشکده علوم پایه 1392

راکتورهای همجوشی، ماشین هایی برای استخراج انرژی هسته ای می باشند. در این راکتورها هسته های عناصر سبک در طی یک واکنش همجوشی هسته ای به هست? سنگین تر تبدیل می شوند که این واکنش با تولید انرژی همراه است. محاسبات نشان می دهند که به منظور داشتن راکتوری بهینه، سوخت همجوشی باید دارای دمایی از مرتب? 10میلیون درج? سانتی گراد و چگالی ای از مرتب? 23^10 ذره بر مترمکعب باشد. بنابراین، مسئل? گرم کردن ومحصورس...

ابراهیم نسب, ستاره, ثابت داریانی, رضا,

Reflection spectra of four porous silicon samples under etching times of 2, 6, 10, and 14 min with current density of 10 mA/cm2 were measured. Reflection spectra behaviors for all samples were the same, but their intensities were different and decreased by increasing the etching time. The similar behavior of reflection spectra could be attributed to the electrolyte solution concentration which ...

Information obtained from nucleus as a bound system of nucleons and from nucleon-nucleon scattering experiments is a strong tool for studying various aspects of nuclear forces. Deuteron-deuteron scattering as a four-nucleon system can provide useful information. So, scattering experiment of a polarized beam of deuteron with kinetic energy of65 MeV/nucleon from a liquid-deuterium target was done...

The effects of including incoherent (bound-electron) and coherent (Rayleigh) scattering in exposure buildup factor calculations for point isotropic gamma ray sources, penetrating a two-layer water-lead shield have been investigated in the gamma ray energy (E?) range of 40 keV to 3 MeV. Incoherent scattering decreases the values of these factors in both layers up to E? ~ 200 keV and the effect i...

Journal: :iranian journal of medical physics 0
seyed milad vahabi energy engineering and physics department, amirkabir university of technology, tehran, iran mojtaba shamsaei zafarghandi energy engineering and physics department, amirkabir university of technology, tehran, iran

introduction dose calculation of tumor and surrounding tissues is essential during prostate brachytherapy. three radioisotopes, namely, 125i, 103pd, and 131cs, are extensively used in this method. in this study, we aimed to calculate the received doses by the prostate and critical organs using the aforementioned radioactive seeds and to investigate the effect of scattering contribution for the ...

Journal: :iranian journal of radiation research 0
v. changizi department of medical physics, faculty of medicine, tehran university of medical sciences, tehran, iran m.a. oghabian department of medical physics, faculty of medicine, tehran university of medical sciences, tehran, iran s. sarkar department of medical physics, faculty of medicine, tehran university of medical sciences, tehran, iran r.d. speller department of medical physics and bioengineering, university college london, london wc1e 6ja, uk a. arab kheradmand department of medical physics, faculty of medicine, tehran university of medical sciences, tehran, iran

abstract background: coherent scattering leads to diffraction effects and especially constructive interferences. theseinterferences carry some information about the molecular structure of the tissue. as breast cancer isthe most widespread cancer in women, this project evaluated the application of small anglex-ray scattering (saxs) for differentiation between normal and cancerous breast tissues....

Journal: :iranian journal of nuclear medicine 2004
nasrollah jabbari hossein rajabi hassan firoozabadi fereidoon rastgoo nahid yaghoobi

introduction: scatter radiation is one of the major sources of error in nuclear medicine data processing. different methods of scatter correction have been introduced in order to improve the quality of data. however the best method is to avoid recording of scatter photons in acquisition. the only difference between scattered and non-scattered photons is the energy. pulse height analyzer is the ...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید